SQLCMD Syntax error executing SQL Express Backup SP

Hi,

I'm pretty much an SQL virgin and have been trying to create an automated backup routine for a single application database in SQL Express 2008 R2. I've been following the procedure defined in kb2019698. When I execute the following command I get the error depicted returned:

sqlcmd -S .\Synchro -E -Q "EXEC sp_BackupDatabases @backupLocation='E:\SQLBackup\', @databaseName=’SYNCHRO’, @backupType='F'"

Creation of stored procedure looks to me to be ok. Only variation I can spot is that I'm trying to do this in SQL Express 2008R2 which isn't listed as a product to which kb2019698 applies.

All help much appreciated.